//package com.retailcloud.commonutils.xss;
//
//import java.util.*;
//import java.util.concurrent.ConcurrentHashMap;
//import java.util.concurrent.ConcurrentMap;
//import java.util.logging.Logger;
//import java.util.regex.Matcher;
//import java.util.regex.Pattern;
//
///**
// *
// * HTML filtering utility for protecting against XSS (Cross Site Scripting).
// *
// * This code is licensed LGPLv3
// *
// * This code is a Java port of the original work in PHP by Cal Hendersen.
// * http://code.iamcal.com/php/lib_filter/
// *
// * The trickiest part of the translation was handling the differences in regex handling
// * between PHP and Java.  These resources were helpful in the process:
// *
// * http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html
// * http://us2.php.net/manual/en/reference.pcre.pattern.modifiers.php
// * http://www.regular-expressions.info/modifiers.html
// *
// * A note on naming conventions: instance variables are prefixed with a "v"; global
// * constants are in all caps.
// *
// * Sample use:
// * String input = ...
// * String clean = new HTMLFilter().filter( input );
// *
// * The class is not thread safe. Create a new instance if in doubt.
// *
// * If you find bugs or have suggestions on improvement (especially regarding
// * performance), please contact us.  The latest version of this
// * source, and our contact details, can be found at http://xss-html-filter.sf.net
// *
// * @author Joseph O'Connell
// * @author Cal Hendersen
// * @author Michael Semb Wever
// */
//public final class HTMLFilter {
//
//    /** regex flag union representing /si modifiers in php **/
//    private static final int REGEX_FLAGS_SI = Pattern.CASE_INSENSITIVE | Pattern.DOTALL;
//    private static final Pattern P_COMMENTS = Pattern.compile("<!--(.*?)-->", Pattern.DOTALL);
//    private static final Pattern P_COMMENT = Pattern.compile("^!--(.*)--$", REGEX_FLAGS_SI);
//    private static final Pattern P_TAGS = Pattern.compile("<(.*?)>", Pattern.DOTALL);
//    private static final Pattern P_END_TAG = Pattern.compile("^/([a-z0-9]+)", REGEX_FLAGS_SI);
//    private static final Pattern P_START_TAG = Pattern.compile("^([a-z0-9]+)(.*?)(/?)$", REGEX_FLAGS_SI);
//    private static final Pattern P_QUOTED_ATTRIBUTES = Pattern.compile("([a-z0-9]+)=([\"'])(.*?)\\2", REGEX_FLAGS_SI);
//    private static final Pattern P_UNQUOTED_ATTRIBUTES = Pattern.compile("([a-z0-9]+)(=)([^\"\\s']+)", REGEX_FLAGS_SI);
//    private static final Pattern P_PROTOCOL = Pattern.compile("^([^:]+):", REGEX_FLAGS_SI);
//    private static final Pattern P_ENTITY = Pattern.compile("&#(\\d+);?");
//    private static final Pattern P_ENTITY_UNICODE = Pattern.compile("&#x([0-9a-f]+);?");
//    private static final Pattern P_ENCODE = Pattern.compile("%([0-9a-f]{2});?");
//    private static final Pattern P_VALID_ENTITIES = Pattern.compile("&([^&;]*)(?=(;|&|$))");
//    private static final Pattern P_VALID_QUOTES = Pattern.compile("(>|^)([^<]+?)(<|$)", Pattern.DOTALL);
//    private static final Pattern P_END_ARROW = Pattern.compile("^>");
//    private static final Pattern P_BODY_TO_END = Pattern.compile("<([^>]*?)(?=<|$)");
//    private static final Pattern P_XML_CONTENT = Pattern.compile("(^|>)([^<]*?)(?=>)");
//    private static final Pattern P_STRAY_LEFT_ARROW = Pattern.compile("<([^>]*?)(?=<|$)");
//    private static final Pattern P_STRAY_RIGHT_ARROW = Pattern.compile("(^|>)([^<]*?)(?=>)");
//    private static final Pattern P_AMP = Pattern.compile("&");
//    private static final Pattern P_QUOTE = Pattern.compile("<");
//    private static final Pattern P_LEFT_ARROW = Pattern.compile("<");
//    private static final Pattern P_RIGHT_ARROW = Pattern.compile(">");
//    private static final Pattern P_BOTH_ARROWS = Pattern.compile("<>");
//
//    // @xxx could grow large... maybe use sesat's ReferenceMap
//    private static final ConcurrentMap<String,Pattern> P_REMOVE_PAIR_BLANKS = new ConcurrentHashMap<String, Pattern>();
//    private static final ConcurrentMap<String,Pattern> P_REMOVE_SELF_BLANKS = new ConcurrentHashMap<String, Pattern>();
//
//    /** set of allowed html elements, along with allowed attributes for each element **/
//    private final Map<String, List<String>> vAllowed;
//    /** counts of open tags for each (allowable) html element **/
//    private final Map<String, Integer> vTagCounts = new HashMap<String, Integer>();
//
//    /** html elements which must always be self-closing (e.g. "<img />") **/
//    private final String[] vSelfClosingTags;
//    /** html elements which must always have separate opening and closing tags (e.g. "<b></b>") **/
//    private final String[] vNeedClosingTags;
//    /** set of disallowed html elements **/
//    private final String[] vDisallowed;
//    /** attributes which should be checked for valid protocols **/
//    private final String[] vProtocolAtts;
//    /** allowed protocols **/
//    private final String[] vAllowedProtocols;
//    /** tags which should be removed if they contain no content (e.g. "<b></b>" or "<b />") **/
//    private final String[] vRemoveBlanks;
//    /** entities allowed within html markup **/
//    private final String[] vAllowedEntities;
//    /** flag determining whether comments are allowed in input String. */
//    private final boolean stripComment;
//    private final boolean encodeQuotes;
//    private boolean vDebug = false;
//    /**
//     * flag determining whether to try to make tags when presented with "unbalanced"
//     * angle brackets (e.g. "<b text </b>" becomes "<b> text </b>").  If set to false,
//     * unbalanced angle brackets will be html escaped.
//     */
//    private final boolean alwaysMakeTags;
//
//    /** Default constructor.
//     *
//     */
//    public HTMLFilter() {
//        vAllowed = new HashMap<>();
//
//        final ArrayList<String> a_atts = new ArrayList<String>();
//        a_atts.add("href");
//        a_atts.add("target");
//        vAllowed.put("a", a_atts);
//
//        final ArrayList<String> img_atts = new ArrayList<String>();
//        img_atts.add("src");
//        img_atts.add("width");
//        img_atts.add("height");
//        img_atts.add("alt");
//        vAllowed.put("img", img_atts);
//
//        final ArrayList<String> no_atts = new ArrayList<String>();
//        vAllowed.put("b", no_atts);
//        vAllowed.put("strong", no_atts);
//        vAllowed.put("i", no_atts);
//        vAllowed.put("em", no_atts);
//
//        vSelfClosingTags = new String[]{"img"};
//        vNeedClosingTags = new String[]{"a", "b", "strong", "i", "em"};
//        vDisallowed = new String[]{};
//        vAllowedProtocols = new String[]{"http", "mailto", "https"}; // no ftp.
//        vProtocolAtts = new String[]{"src", "href"};
//        vRemoveBlanks = new String[]{"a", "b", "strong", "i", "em"};
//        vAllowedEntities = new String[]{"amp", "gt", "lt", "quot"};
//        stripComment = true;
//        encodeQuotes = true;
//        alwaysMakeTags = true;
//    }
//
//    /** Set debug flag to true. Otherwise use default settings. See the default constructor.
//     *
//     * @param debug turn debug on with a true argument
//     */
//    public HTMLFilter(final boolean debug) {
//        this();
//        vDebug = debug;
//
//    }
//
//    /** Map-parameter configurable constructor.
//     *
//     * @param conf map containing configuration. keys match field names.
//     */
//    public HTMLFilter(final Map<String,Object> conf) {
//
//        assert conf.containsKey("vAllowed") : "configuration requires vAllowed";
//        assert conf.containsKey("vSelfClosingTags") : "configuration requires vSelfClosingTags";
//        assert conf.containsKey("vNeedClosingTags") : "configuration requires vNeedClosingTags";
//        assert conf.containsKey("vDisallowed") : "configuration requires vDisallowed";
//        assert conf.containsKey("vAllowedProtocols") : "configuration requires vAllowedProtocols";
//        assert conf.containsKey("vProtocolAtts") : "configuration requires vProtocolAtts";
//        assert conf.containsKey("vRemoveBlanks") : "configuration requires vRemoveBlanks";
//        assert conf.containsKey("vAllowedEntities") : "configuration requires vAllowedEntities";
//
//        vAllowed = Collections.unmodifiableMap((HashMap<String, List<String>>) conf.get("vAllowed"));
//        vSelfClosingTags = (String[]) conf.get("vSelfClosingTags");
//        vNeedClosingTags = (String[]) conf.get("vNeedClosingTags");
//        vDisallowed = (String[]) conf.get("vDisallowed");
//        vAllowedProtocols = (String[]) conf.get("vAllowedProtocols");
//        vProtocolAtts = (String[]) conf.get("vProtocolAtts");
//        vRemoveBlanks = (String[]) conf.get("vRemoveBlanks");
//        vAllowedEntities = (String[]) conf.get("vAllowedEntities");
//        stripComment =  conf.containsKey("stripComment") ? (Boolean) conf.get("stripComment") : true;
//        encodeQuotes = conf.containsKey("encodeQuotes") ? (Boolean) conf.get("encodeQuotes") : true;
//        alwaysMakeTags = conf.containsKey("alwaysMakeTags") ? (Boolean) conf.get("alwaysMakeTags") : true;
//    }
//
//    private void reset() {
//        vTagCounts.clear();
//    }
//
//    private void debug(final String msg) {
//        if (vDebug) {
//            Logger.getAnonymousLogger().info(msg);
//        }
//    }
//
//    //---------------------------------------------------------------
//    // my versions of some PHP library functions
//    public static String chr(final int decimal) {
//        return String.valueOf((char) decimal);
//    }
//
//    public static String htmlSpecialChars(final String s) {
//        String result = s;
//        result = regexReplace(P_AMP, "&amp;", result);
//        result = regexReplace(P_QUOTE, "&quot;", result);
//        result = regexReplace(P_LEFT_ARROW, "&lt;", result);
//        result = regexReplace(P_RIGHT_ARROW, "&gt;", result);
//        return result;
//    }
//
//    //---------------------------------------------------------------
//    /**
//     * given a user submitted input String, filter out any invalid or restricted
//     * html.
//     *
//     * @param input text (i.e. submitted by a user) than may contain html
//     * @return "clean" version of input, with only valid, whitelisted html elements allowed
//     */
//    public String filter(final String input) {
//        reset();
//        String s = input;
//
//        debug("************************************************");
//        debug("              INPUT: " + input);
//
//        s = escapeComments(s);
//        debug("     escapeComments: " + s);
//
//        s = balanceHTML(s);
//        debug("        balanceHTML: " + s);
//
//        s = checkTags(s);
//        debug("          checkTags: " + s);
//
//        s = processRemoveBlanks(s);
//        debug("processRemoveBlanks: " + s);
//
//        s = validateEntities(s);
//        debug("    validateEntites: " + s);
//
//        debug("************************************************\n\n");
//        return s;
//    }
//
//    public boolean isAlwaysMakeTags(){
//        return alwaysMakeTags;
//    }
//
//    public boolean isStripComments(){
//        return stripComment;
//    }
//
//    private String escapeComments(final String s) {
//        final Matcher m = P_COMMENTS.matcher(s);
//        final StringBuffer buf = new StringBuffer();
//        if (m.find()) {
//            final String match = m.group(1); //(.*?)
//            m.appendReplacement(buf, Matcher.quoteReplacement("<!--" + htmlSpecialChars(match) + "-->"));
//        }
//        m.appendTail(buf);
//
//        return buf.toString();
//    }
//
//    private String balanceHTML(String s) {
//        if (alwaysMakeTags) {
//            //
//            // try and form html
//            //
//            s = regexReplace(P_END_ARROW, "", s);
//            s = regexReplace(P_BODY_TO_END, "<$1>", s);
//            s = regexReplace(P_XML_CONTENT, "$1<$2", s);
//
//        } else {
//            //
//            // escape stray brackets
//            //
//            s = regexReplace(P_STRAY_LEFT_ARROW, "&lt;$1", s);
//            s = regexReplace(P_STRAY_RIGHT_ARROW, "$1$2&gt;<", s);
//
//            //
//            // the last regexp causes '<>' entities to appear
//            // (we need to do a lookahead assertion so that the last bracket can
//            // be used in the next pass of the regexp)
//            //
//            s = regexReplace(P_BOTH_ARROWS, "", s);
//        }
//
//        return s;
//    }
//
//    private String checkTags(String s) {
//        Matcher m = P_TAGS.matcher(s);
//
//        final StringBuffer buf = new StringBuffer();
//        while (m.find()) {
//            String replaceStr = m.group(1);
//            replaceStr = processTag(replaceStr);
//            m.appendReplacement(buf, Matcher.quoteReplacement(replaceStr));
//        }
//        m.appendTail(buf);
//
//        s = buf.toString();
//
//        // these get tallied in processTag
//        // (remember to reset before subsequent calls to filter method)
//        for (String key : vTagCounts.keySet()) {
//            for (int ii = 0; ii < vTagCounts.get(key); ii++) {
//                s += "</" + key + ">";
//            }
//        }
//
//        return s;
//    }
//
//    private String processRemoveBlanks(final String s) {
//        String result = s;
//        for (String tag : vRemoveBlanks) {
//            if(!P_REMOVE_PAIR_BLANKS.containsKey(tag)){
//                P_REMOVE_PAIR_BLANKS.putIfAbsent(tag, Pattern.compile("<" + tag + "(\\s[^>]*)?></" + tag + ">"));
//            }
//            result = regexReplace(P_REMOVE_PAIR_BLANKS.get(tag), "", result);
//            if(!P_REMOVE_SELF_BLANKS.containsKey(tag)){
//                P_REMOVE_SELF_BLANKS.putIfAbsent(tag, Pattern.compile("<" + tag + "(\\s[^>]*)?/>"));
//            }
//            result = regexReplace(P_REMOVE_SELF_BLANKS.get(tag), "", result);
//        }
//
//        return result;
//    }
//
//    private static String regexReplace(final Pattern regex_pattern, final String replacement, final String s) {
//        Matcher m = regex_pattern.matcher(s);
//        return m.replaceAll(replacement);
//    }
//
//    private String processTag(final String s) {
//        // ending tags
//        Matcher m = P_END_TAG.matcher(s);
//        if (m.find()) {
//            final String name = m.group(1).toLowerCase();
//            if (allowed(name)) {
//                if (!inArray(name, vSelfClosingTags)) {
//                    if (vTagCounts.containsKey(name)) {
//                        vTagCounts.put(name, vTagCounts.get(name) - 1);
//                        return "</" + name + ">";
//                    }
//                }
//            }
//        }
//
//        // starting tags
//        m = P_START_TAG.matcher(s);
//        if (m.find()) {
//            final String name = m.group(1).toLowerCase();
//            final String body = m.group(2);
//            String ending = m.group(3);
//
//            //debug( "in a starting tag, name='" + name + "'; body='" + body + "'; ending='" + ending + "'" );
//            if (allowed(name)) {
//                String params = "";
//
//                final Matcher m2 = P_QUOTED_ATTRIBUTES.matcher(body);
//                final Matcher m3 = P_UNQUOTED_ATTRIBUTES.matcher(body);
//                final List<String> paramNames = new ArrayList<String>();
//                final List<String> paramValues = new ArrayList<String>();
//                while (m2.find()) {
//                    paramNames.add(m2.group(1)); //([a-z0-9]+)
//                    paramValues.add(m2.group(3)); //(.*?)
//                }
//                while (m3.find()) {
//                    paramNames.add(m3.group(1)); //([a-z0-9]+)
//                    paramValues.add(m3.group(3)); //([^\"\\s']+)
//                }
//
//                String paramName, paramValue;
//                for (int ii = 0; ii < paramNames.size(); ii++) {
//                    paramName = paramNames.get(ii).toLowerCase();
//                    paramValue = paramValues.get(ii);
//
////          debug( "paramName='" + paramName + "'" );
////          debug( "paramValue='" + paramValue + "'" );
////          debug( "allowed? " + vAllowed.get( name ).contains( paramName ) );
//
//                    if (allowedAttribute(name, paramName)) {
//                        if (inArray(paramName, vProtocolAtts)) {
//                            paramValue = processParamProtocol(paramValue);
//                        }
//                        params += " " + paramName + "=\"" + paramValue + "\"";
//                    }
//                }
//
//                if (inArray(name, vSelfClosingTags)) {
//                    ending = " /";
//                }
//
//                if (inArray(name, vNeedClosingTags)) {
//                    ending = "";
//                }
//
//                if (ending == null || ending.length() < 1) {
//                    if (vTagCounts.containsKey(name)) {
//                        vTagCounts.put(name, vTagCounts.get(name) + 1);
//                    } else {
//                        vTagCounts.put(name, 1);
//                    }
//                } else {
//                    ending = " /";
//                }
//                return "<" + name + params + ending + ">";
//            } else {
//                return "";
//            }
//        }
//
//        // comments
//        m = P_COMMENT.matcher(s);
//        if (!stripComment && m.find()) {
//            return  "<" + m.group() + ">";
//        }
//
//        return "";
//    }
//
//    private String processParamProtocol(String s) {
//        s = decodeEntities(s);
//        final Matcher m = P_PROTOCOL.matcher(s);
//        if (m.find()) {
//            final String protocol = m.group(1);
//            if (!inArray(protocol, vAllowedProtocols)) {
//                // bad protocol, turn into local anchor link instead
//                s = "#" + s.substring(protocol.length() + 1, s.length());
//                if (s.startsWith("#//")) {
//                    s = "#" + s.substring(3, s.length());
//                }
//            }
//        }
//
//        return s;
//    }
//
//    private String decodeEntities(String s) {
//        StringBuffer buf = new StringBuffer();
//
//        Matcher m = P_ENTITY.matcher(s);
//        while (m.find()) {
//            final String match = m.group(1);
//            final int decimal = Integer.decode(match).intValue();
//            m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
//        }
//        m.appendTail(buf);
//        s = buf.toString();
//
//        buf = new StringBuffer();
//        m = P_ENTITY_UNICODE.matcher(s);
//        while (m.find()) {
//            final String match = m.group(1);
//            final int decimal = Integer.valueOf(match, 16).intValue();
//            m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
//        }
//        m.appendTail(buf);
//        s = buf.toString();
//
//        buf = new StringBuffer();
//        m = P_ENCODE.matcher(s);
//        while (m.find()) {
//            final String match = m.group(1);
//            final int decimal = Integer.valueOf(match, 16).intValue();
//            m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
//        }
//        m.appendTail(buf);
//        s = buf.toString();
//
//        s = validateEntities(s);
//        return s;
//    }
//
//    private String validateEntities(final String s) {
//        StringBuffer buf = new StringBuffer();
//
//        // validate entities throughout the string
//        Matcher m = P_VALID_ENTITIES.matcher(s);
//        while (m.find()) {
//            final String one = m.group(1); //([^&;]*)
//            final String two = m.group(2); //(?=(;|&|$))
//            m.appendReplacement(buf, Matcher.quoteReplacement(checkEntity(one, two)));
//        }
//        m.appendTail(buf);
//
//        return encodeQuotes(buf.toString());
//    }
//
//    private String encodeQuotes(final String s){
//        if(encodeQuotes){
//            StringBuffer buf = new StringBuffer();
//            Matcher m = P_VALID_QUOTES.matcher(s);
//            while (m.find()) {
//                final String one = m.group(1); //(>|^)
//                final String two = m.group(2); //([^<]+?)
//                final String three = m.group(3); //(<|$)
//                m.appendReplacement(buf, Matcher.quoteReplacement(one + regexReplace(P_QUOTE, "&quot;", two) + three));
//            }
//            m.appendTail(buf);
//            return buf.toString();
//        }else{
//            return s;
//        }
//    }
//
//    private String checkEntity(final String preamble, final String term) {
//
//        return ";".equals(term) && isValidEntity(preamble)
//                ? '&' + preamble
//                : "&amp;" + preamble;
//    }
//
//    private boolean isValidEntity(final String entity) {
//        return inArray(entity, vAllowedEntities);
//    }
//
//    private static boolean inArray(final String s, final String[] array) {
//        for (String item : array) {
//            if (item != null && item.equals(s)) {
//                return true;
//            }
//        }
//        return false;
//    }
//
//    private boolean allowed(final String name) {
//        return (vAllowed.isEmpty() || vAllowed.containsKey(name)) && !inArray(name, vDisallowed);
//    }
//
//    private boolean allowedAttribute(final String name, final String paramName) {
//        return allowed(name) && (vAllowed.isEmpty() || vAllowed.get(name).contains(paramName));
//    }
//}
